deck footer issue

Wood will deteriorate when exposed to a constant wetting and drying, even pressure treated posts have a life expectancy.

I’d install an elevated post base. They make retrofit style like this one if you need to elevate just an inch or so:

https://www.amazon.com/Simpson-Strong-ABA66Z-Z-Max-Adjustable/dp/B000WI35AM

Or if you need more elevation you can use this style:

https://www.homedepot.com/p/Simpson-Strong-Tie-EPB-Hot-Dip-Galvanized-Pier-Block-Elevated-Post-Base-for-4x4-Nominal-Lumber-EPB44PHDG/100506799

Summary: You don’t need to add concrete (your footings are fine) you just need to raise the posts to keep them out of the dirt and moisture.

In addition, the code now requires two deck ties to hold the deck tight to the house. This is extremely important in seismic areas where a house will move differently than decks during earthquakes. Two are required per deck...one at each end of a deck. See a typical tie below:

https://www.google.com/search?q=simpson+dtt2z&rlz=1CDGOYI_enUS900US900&oq=simpson+dtt&aqs=chrome.0.0l2j69i57j0.13773j0j4&hl=en-US&sourceid=chrome-mobile&ie=UTF-8#imgrc=Z5lnOd0lAk7eyM